June 2013
Volume 54, Issue 15
Free
ARVO Annual Meeting Abstract  |   June 2013
NO Activates Src Family Kinase and Inhibits Na,K-ATPase Activity in Nonpigmented Ciliary Epithelium
Author Affiliations & Notes
  • Mohammad Shahidullah
    Physiology, Univ of Arizona, College of Medicine, Tucson, AZ
  • Amritlal Mandal
    Physiology, Univ of Arizona, College of Medicine, Tucson, AZ
  • Guojun Wei
    Physiology, Univ of Arizona, College of Medicine, Tucson, AZ
  • Nicholas Delamere
    Physiology, Univ of Arizona, College of Medicine, Tucson, AZ
  • Footnotes
    Commercial Relationships Mohammad Shahidullah, None; Amritlal Mandal, None; Guojun Wei, None; Nicholas Delamere, None
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science June 2013, Vol.54, 3700. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Mohammad Shahidullah, Amritlal Mandal, Guojun Wei, Nicholas Delamere, ; NO Activates Src Family Kinase and Inhibits Na,K-ATPase Activity in Nonpigmented Ciliary Epithelium. Invest. Ophthalmol. Vis. Sci. 2013;54(15):3700.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose: We reported earlier that the nitric oxide (NO) donor SNP reduces aqueous humor secretion in isolated porcine eyes and inhibits Na,K-ATPase activity in nonpigmented ciliary epithelium (NPE) through a cGMP/PKG-mediated pathway. Here we examine the mechanism that links SNP-induced PKG activation to inhibition of Na,K-ATPase activity.

Methods: Porcine NPE was established in primary culture. Na,K-ATPase activity was measured as ouabain-sensitive ATP hydrolysis in NPE lysates. Na,K-ATPase-mediated transport was measured as ouabain-sensitive potassium (86Rb) uptake by intact NPE monolayers grown on permeable supports. Protein phosphorylation was studied by western blot analysis.

Results: SNP and 8-Br-cGMP both inhibited Na,K-ATPase activity and 86Rb uptake and the Src family kinase (SFK) inhibitor PP2 blocked the responses. SNP and 8-Br-cGMP caused activation of SFK, ERK1/2 and p-38 MAPK as indicated by increased phosphorylation. Although it is selective for SFK, PP2 prevented SNP-mediated activation of ERK1/2 and p-38 MAPK as well as SFK. The selective ERK1/2 inhibitor U0126 prevented SNP-induced ERK1/2 and p-38 MAPK activation but not SNP-induced SFK phosphorylation or Na,K-ATPase inhibition. SNP did not detectably change Na,K-ATPase α1 abundance on the plasma membrane or Ser16 phosphorylation of Na,K-ATPase α1. On the other hand, SNP-treated NPE displayed significant phosphorylation of Na,K-ATPase α1 at Tyr10.

Conclusions: NO elicits phosphorylation of SFK through a cGMP/PKG pathway and Na,K-ATPase activity reduction appears to be SFK-mediated. The Na,K-ATPase response is associated with Tyr10 phosphorylation of Na,K-ATPase α1 protein. NO-elicited activation of ERK1/2 and p-38 MAPK does not play a role in the regulation of Na,K-ATPase activity.

Keywords: 606 NaK ATPase • 427 aqueous • 570 ion transporters  
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×